The cotyledons of etiolated seedlings from terrestrial flowering plants must emerge from the soil surface, while roots must penetrate the soil to ensure plant survival. We show here that the soil emergence-related transcription factor PHYTOCHROME-INTERACTING FACTOR 3 (PIF3) controls root penetration via transducing external signals perceived by the receptor kinase FERONIA (FER) in Arabidopsis thaliana. The loss of FER function in Arabidopsis and soybean (Glycine max) mutants resulted in a severe defect in root penetration into agar medium or hard soil. Single-cell RNA sequencing (scRNA-seq) profiling of Arabidopsis roots identified a distinct cell clustering pattern, especially for root cap cells, and identified PIF3 as a FER-regulated transcription factor. Biochemical, imaging, and genetic experiments confirmed that PIF3 is required for root penetration into soil. Moreover, FER interacted with and stabilized PIF3 to modulate the expression of mechanosensitive ion channel PIEZO and the sloughing of outer root cap cells.

陆生开花植物的黄化幼苗的子叶必须从土壤表面伸出，而根必须穿透土壤以确保植物的生存。我们在此表明​​，与土壤出苗相关的转录因子 PHYTOCHROME-INTERACTING FACTOR 3 (PIF3) 通过转导拟南芥中受体激酶 FERONIA (FER) 感知的外部信号来控制根系渗透。拟南芥和大豆 ( Glycine max ) 突变体中 FER 功能的丧失导致根部渗透到琼脂培养基或硬土中的严重缺陷。拟南芥根的单细胞 RNA 测序 (scRNA-seq) 分析发现了独特的细胞聚类模式，尤其是根冠细胞，并确定 PIF3 是 FER 调节的转录因子。生化、成像和遗传实验证实，PIF3 是根部渗透到土壤中所必需的。此外，FER 与 PIF3 相互作用并稳定 PIF3，以调节机械敏感离子通道 PIEZO 的表达和外根冠细胞的脱落。